Anti-disturbance delay fuze

ABSTRACT

The invention relates to an anti-disturbance delay fuze for safing, arming and initiating a munition. The present invention permits a munition to be safely handled when launched, to remain inoperative during a first interval of time equivalent to the period that this munition is being dispersed to the target area, to be responsive immediately to subsequent disturbance, and to cause initiation after a second interval of time after dispersal when there has been no disturbance. The present invention comprises a housing having a central bore, a delay disc counter bore in an open end and an axial counter bore in a partially closed end, a biased triggering means rotatably positioned in the axial counter bore for arming the munition after a first period of time and firing the munition after a second period of time, a firing pin means operatively affixed to the housing and releasably held in the triggering means, a fuze cover circumambient to the housing having an integrally formed disturbance weight position lock and pivot depending for the inside surface of the cover, and a delay means operatively positioned intermediate to the disturbance means and the triggering means for keeping the disturbance means inoperative during the first time period and initiating the munition upon movement after the first time period, and for initiation of the munition after a second time period where there has been no movement of the munition during the interval of time between the first and second periods.

EJnited States Patent Savarese, Jr.

[ 1 Oct. 30, 1973 ANTI-DISTURBANCE DELAY FUZE [75] Inventor: Antonio Savarese, Jr., Morris Plains,

[73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[22] Filed: June 14, 1972 [21] Appl. No.: 263,719

[52] US. Cl 102/8, 102/81, 102/83 [51] Int. Cl. F42b 23/26 [58] Field of Search 102/70, 76, 79, 7.2, 102/8, 75, 81,83

[56] References Cited UNITED STATES PATENTS 3,094,935 6/1963 Mettler 102/8 3,195,459 7/1965 Reed,Jr 102/7.2 3,447,461 6/1969 Lapof 102/8 3,282,212 11/1966 Romano... 102/8 3,646,889 3/1972 Davis 102/7.2

Primary Examiner-Samuel W. Engle Atmrneyl-larry M. Saragovitz et a1.

[57] ABSTRACT The invention relates to an anti-disturbance delay fuze for sating, arming and initiating a munition. The pres- C'XUQ F l l 1 ent invention permits a munition to be safely handled when launched, to remain inoperative during a first interval of time equivalent to the period that this munition is being dispersed to the target area, to be responsive immediately to subsequent disturbance, and to cause initiation after a second interval of time after dispersal when there has been no disturbance.

The present invention comprises a housing having a central bore, a delay disc counter bore in an open end and an axial counter bore in a partially closed end, a biased triggering means rotatably positioned in the axial counter bore for arming the munition after a first period of time and tiring the munition after a second period of time, a firing pin means operatively affixed to the housing and releasably held in the triggering means, a fuze cover circumambient to the housing having an integrally formed disturbance weight position lock and pivot depending for the inside surface of the cover, and a delay means operatively positioned intermediate to the disturbance means and the triggering means for keeping the disturbance means inoperative during the first time period and initiating the munition upon movement after the first time period, and for initiation of the munition after a second time period where there has been no movement of the munition during the interval of time between the first and second periods.

6 Claims, 6 Drawing Figures PATENTEB 0U 30 8375 saw 20$ 3 ANTI-DISTURBANCE DELAY FUZE GOVERNMENTAL INTEREST The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION Various means have been used by prior art delay fuzed mines to permit the mine to be aerially dispersed without endangering the personnel dispensing the munition nor exploding other near-by falling munition while in the air. Prior art fuzes have used the dashpot concept to provide random delays which will keep the fuze in a safe position varying from minutes to days. Some of the prior art devices have combined this delay function with an anti-disturbance mechanism which permits the device to explode if disturbed after the delay period has elapsed. One of the problems with such prior art has been that the disturbance feature of the switch is functioning as a contact of a terminal of an electrical switch which is connected to and associated with electrical circuitry. In some of these prior art devices, the disturbance feature utilizes the vibrating or flexing characteristic of a cantilever or double end supported member to close the switch.

Other devices utilize the free rolling motion of a ball to contact a post and a housing, or to simultaneously contact a pair of terminal posts to effect the closure of the electrical switch. In all of these prior art devices the use of an electrical circuit to initiate an explosion requires the use of an electrical source of power such as a battery which has a limited shelf life, or some other electrical energy source such as a piezo-electric crystal and condenser combination which is relatively expensive to use and requires for operation of the crystal, a significant force to generate the voltage required.

Those prior art delay type fuzes which do not utilize an anti-disturbance device in combination with the delay mechanism, do not restrict the movement of enemy troops in the target area where the delay mechanism hasnt completed the arming cycle. Under such conditions when the enemy troops choose to remain active, they could kick, step on, or otherwise disturb the grenade without causing it to explode.

The present invention overcomes the aforementioned problems by the addition of a simple, inexpensive and reliable mechanically operative disturbance feature to the delay mechanism thereby permitting the munition to function immediately after a first relatively short period of delay, and in the event that the munition has not been disturbed after the first period initiation is caused after a second subsequent period.

SUMMARY OF THE INVENTION The present invention relates to an improved mechanical anti-disturbance device in combination with a delay fuze. In the safe position, a lever locking means is operatively positioned intermediate to a pivoted pendulous mass. The latter is designed to lock a detented spring-biased firing pin in a non-operative position. One end of the pendulous disturbance device has a support column mounted thereon and the other end has an integral locking detent which aligns itself with a projection in the fuze cover. A delay disc is operatively positioned underneath the pendulous mass and has a matching support column thereon which, in the safe" position, completely inhibits the disturbance device from operating. In the armed position, the two support columns are in line in a frictionally balanced position and subject to being upset by movement of fuze by either enemy troops or by a delay rotor vane after a finite period of time. Intermediate to the delay disc and a rotationally biased delay rotor is a fluid containing sac holding therein a silicone gum. After launch and during the time that the munition is being delivered to the target area, a centrifugally responsive mechanism (not shown) releases the delay rotor so that it can start to rotate. After elapse of a first period of time running from the time of release of the rotor to the release of the disturbance weight from its lock position, the device may be activated by movement of the fuze. Vanes attached to the delay rotor prevent rapid rotation of the rotor because the viscous fluid is constrictively made to flow between a narrow gap existing between the vanes and the underneath side of the delay disc. A spring loaded firing pin is positioned over a detonator by a ball detent means. The detent ball is operatively positioned in the rotor housing so that it rides the delay rotor shaft and a recess in the firing pin during the time that the fuze is in the safe" or armed state. After the fuze has been armed, by release of the locking lever and by the rotation of the delay rotor, the continued rotation of the delay rotor causes a recess in the delay rotor to present itself the detent ball, freeing the ball from the firing pin recess, and thereby permitting it to forcibly strike a detonator positioned thereunder after the lapse of a second period of time.

One of the objects of this invention is to provide a mechanical antidisturbance feature to a delay fuze.

Another object of this invention is to provide a mechanical anti-disturbance device and delay means wherein the former may be activated after a first delay period.

Another object of this invention is to provide an antidisturbance delay type fuze which will initiate a spring loaded firing pin due to the rotational movement of a pivotal pendulous mass.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric, partial cut-away, crosssectional view of the anti-disturbance delay portion of the fuze showing the position of the major elements while the fuze is in the safe position.

FIG. 2 is a top view of the fuze taken along line 2-2 of the drawing illustrated in FIG. 1.

FIG. 3 is a cross-sectional view taken along line 3-3 of the drawing illustrated in FIG. 1 in order to'show the constructional details of the delay rotor, firing pin, ball detent and rotor shaft ball recess.

FIG. 4 is a radial cross-sectional view thru the longitudinal axis taken along line 4-4 of the drawing illustrated in FIG. 3 in order to show the functional relationship of the ball detent locking means with the delay rotor.

FIG. 5 is an isometric, partial cut-away, crosssectional view of the fuze showing the operative position of its major elements after munition has come to rest and the rotor vane has released the disturbance locking lever so that the fuze is placed in an armed position.

FIG. 6 is an isometric, partial, cut-away, crosssectional view of the fuze in the fired position.

Throughout the following description like reference numerals are used to denote like parts of the drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a fuzing device which will permit a munition to be safely handled when launched, to remain inoperative during a first interval of time equivalent to dispersal to the target area, to be responsive immediately to subsequent disturbance after dispersion, and to initiate the munition causing it to self-destruct after a second period of time in the event there is no disturbance of the munition after the first interval of time. In its broader aspects, the device is intended to provide an anti-disturbance and selfdestruct feature to a delay fuze.

Referring now to FIGS. 1-4 showing the device in the safe" position, a spring loaded firing pin shaft 10 is held within a delay rotor housing 12 in firing pin housing bore 14 and an internal annular rotor groove 16 of a delay rotor 22 on its bottom end 23 by the ball lock 18. The ball 18 is located in the delay rotor 22 intermediate to a restraining rotor shaft 20, and a D-shaped firing pin recess 24 which prevents the release of ball 18 and the actuation of the firing pin 10. A delay rotor shaft radial recess 26 is oppositely disposed, as shown in FIGS. 3 and 4 from the firing pin 10. When the rotor shaft recess 26 is rotated about the fuze longitudinal axis 27 so that it presents itself to the ball lock 18, the latter is pushed into the shaft recess by a horizontal component of force exerted by the spring loaded firing pin 10 thereby freeing the firing pin 10 and driving it forcibly in a downward direction, into a detonator 28. A delay sac disc 30 is supported by housing disc counterbore 31 and is pivotably restrained at point A by the housing wall 13. When the device is in the safe position an upwardly protruding disc switch contact column 32, attached to the upper side of the sac disc 30, is aligned with a similarly shaped downwardly protruding disturbance member switch contact column 34 located on one end of the pivotal member 35 which can rotate in a plane perpendicular to the longitudinal axis 27. In the aforementioned safe position the two aligned contacts form a solid column which together with the pivotable restraint at point A holds the delay sac disc in place against the delay rotor vanes 44, 48; 50. Proximate to the point A the disc 30 has an elongated disturbance weight release lever clearance hole 36 therein, through which a U-shaped disturbance weight release lever 38 is pivotally held by pivot 40 so that it passes through the elongated hole 36. The lower release lever leg 42, in the safe position, is held up by one long vane 44 of the delay rotor 22. The vane is horizontally positioned on the rotor top end 25. The other three radially positioned vanes 46 (not shown), 48 and 50 respectively are shortened in order to clear the release lever 42. When the disturbance weight U- shaped release lever 38 is being held up by the delay rotor long vane 44, the upper release lever leg 54 holds a spring biased cantilever supported disturbance weight 56, located on the other end of the pivotal disturbance member 35, so that it engages a disturbance weight position lock circular protrusion 58. The position lock 58 is formed out of fuze cover 60 and protrudes in a downward direction toward the rotor 22 and is aligned with and slidably fits into a disturbance weight counter bore 62. The disturbance weight release lever 38 holds the weight 56 in a locked position in opposition to a downward force exerted by a biased disturbance weight flexible moment arm 64. The flexible moment arm 64 is a flat spring which holds the disturbance weight 56 off the position lock 58 when unrestricted by the disturbance weight release lever 38. The biased spring 64 has sufficient spring tension therein to keep the disturbance weight 56 free of the lock 58 regardless of the orientation of the fuze after dispersal. The flexible moment arm 64, of the disturbance lever means, is attached to the disturbance lever switch contact column 34 at point B and is preset at an angle so that when the fuze is in an armed position, as shown in FIG. 5, the disturbance weight 56 is free to pivot about disturbance switch pivot 66. A pliable sealed delay sac 68 is operatively positioned intermediate to the underside of delay sac disc 30 and the top of the delay rotor vanes 44, 46, 48 and 50, so that the sac 68 clears the lower release lever leg 42. A viscous fluid 70, such as silicone gum, is contained within the sac 68. A biased helical wound spring 72 having one end 76 anchored by pin 74 which is in turn affixed to delay rotor housing 12, and the other end 78 fixed to rotor 22 provides the necessary torsional force to rotate the rotor 22 through the armed or fired positions shown in FIGS. 5 and 6 respectively. A delay rotor shaft pin 80 in combination with the rotor housing counter bore 88 keeps the delay rotor 22 so that it may concentrically rotate about the fuze longitudinal axis 27 and freely within the delay rotor central housing bore 84.

Referring now to FIG. 5, showing the fuze in the armed position, the delay rotor 22 has rotated in a counter-clockwise direction, when looking at the rotor 22 from a top view, so that the long vane 44 no longer supports the lower release lever leg 42 thereby permitting the upper release lever leg 54 to release the distur; bance weight 56 and to disengage itself from position lock 58. Any motion of the fuze by enemy troops not absolutely parallel to the longitudinal axis 27 will cause the disturbance weight 56 to pivot about the switch pivot 66.

FIG. 6 shows the fuze in a fired position caused by a time delay of sufficient duration to rotate the delay rotor 22 approximately so that slot 26 presents itself to ball lock 18. When the delay rotor shaft recess 26 aligns itself with the ball lock 18 the firing pin biased spring 86, which is fixed to firing pin shaft 10 on one end 92 and to housing 12 on the other end 94, will drive the firing pin point into the detonator 28 thereby initiating the munition.

In operation, the munition is armed by the centrifugal force of spin. This force causes the detonator 28 to move in a position directly under the firing pin 10. A mechanism (not shown) releases the delay rotor 22 permitting it to begin to slowly rotate. After rotating the distance necessary for the long vane 44 to clear the lower release lever 42, the disturbance weight 56 becomes disengaged from the disturbance weight position lock 58. The delay between arming the munition by movement of detonator 28 into position as shown in FIGS. 1, 5, & 6 and release of the disturbance weight 56 permits the munition to come to rest after being delivered to the target area. In the event that the fuze is disturbed, before the delay rotor 22 rotates and causes radial recess 26 to present itself to ball lock 18, the disturbance weight 56 will move relative to the rest of the fuze, since it is mounted on a flexible moment arm 64 and has a measurable amount of inertia. Since the flexible moment arm 64 is a fiat spring, the motion of the disturbance weight 56 will be directed towards movement in a plane parallel to the delay sac disc 30. The motion will result in the disturbance weight 56 rotating about the disturbance switch pivot 66 causing the disturbance lever switch contact column 34 to move off the disc switch contact column 32. The aligned columns holding the delay sac disc 30 in position will therefore be broken. The delay rotor 22 will now force the sac disc 30 out of position and allow the delay rotor to swing around rapidly, unrestricted by the fluid filled delay sac 68 releasing the ball lock 18 into the shaft recess 26 causing the firing pin to forcibly hit the detonator 28 thereby firing the munition.

I wish it to be understood that I do not desire to be limited to the exact detail of construction shown and described for obvious modifications will occur to a person skilled in the art.

What is claimed is:

I. An anti-disturbance delay fuze for safing, arming and initiating a munition which comprises:

a cylindrical cup shaped housing having a delay disc counterbore located in an open end and a central bore, and an axial counterbore of smaller diameter than said central bore in a partially closed end;

biased triggering means rotatable positioned in said axial counterbore for arming said munition after a first time period and firing said munition after a second time period;

firing pin means operatively affixed to said housing and releaseably held in said triggering means;

a fuze cover circumambient said housing having an integrally formed disturbance weight position lock and a disturbance switch pivot depending from the inside top surface of said cover;

a disturbance means, held by said switch pivot operatively adjacent to said cover, and rotationally responsive to said munition movement after said first time period; and

a delay means operatively positioned intermediate said disturbance means and said triggering means for keeping said disturbance means inoperative during said first time period, initiating said munitions upon movement of said fuze after expiration of said first time period, and for the initiation of said munition after said second time period.

2. An anti-disturbance delay fuze as recited in claim 1 wherein the triggering means comprises:

a cylindrically shaped rotor having a bottom end with an axially positioned annular groove therein, an axial rotor shaft concentric with said annular groove further including a radially positioned shaft recess for releasably holding said firing pin means therein, a top end having a plurality of bar-shaped vanes radially mounted thereon and extending in a direction normal to said central bore, wherein one of said bar vanes is longer in length; and

a biased helical spring wound around said rotor intermediate said vanes and said bottom end having a first end anchored to said housing and a second end fixed to said rotor.

3. An anti-disturbance delay fuze as recited in claim 2 wherein the firing pin means comprises:

a cylindrical shaft having a flat end and a pointed end, a radial recess transverse to its longitudinal axis and intermediate to said flat and pointed end;

and

a ball lock operatively positioned intermediate said firing pin shaft recess and said rotor shaft for holding said firing pin in a safe position during said first time period, and for releasing said firing pin when said rotor radially positioned recess aligns itself with said ball lock.

4. An anti-disturbance delay fuze as recited in claim 3 wherein the disturbance means comprises:

a pivotal member rotatably held by said switch pivot;

a switch contact column depending from one end of said member;

a bent flexible cantilevered moment arm fixedly attached to the other end of said member; and

a pendulous mass, fixedly attached to said moment arm, so that a counterbore in said mass operatively engages said position lock when said fuze is in a safe position and is free to rotate about said switch pivot when said fuze is in an armed position.

5. An anti-disturbance delay fuze as recited in claim 4 wherein the delay means comprises;

a disc piv'otally held in said disc counterbore, having a disc switch column fixedly attached to its upper side and axially aligned with said member switch column, a U-shaped release lever, including upper and lower legs, said release lever pivotally attached to said disc and operatively positioned so that said upper leg supports said pendulous mass when said triggering means during said first period supports said lower leg; and

a pliable sac having a viscous fluid therein sealed to said disc underneath side intermediate to said disc and said plurality of vanes.

6. An anti-disturbance delay fuze as recited in claim 5 wherein the viscous fluid is a silicone gum. 

1. An anti-disturbance delay fuze for safing, arming and initiating a munition which comprises: a cylindrical cup shaped housing having a delay disc counterbore located in an open end and a central bore, and an axial counterbore of smaller diameter than said central bore in a partially closed end; biased triggering means rotatable positioned in said axial counterbore for arming said munition after a first time period and firing said munition after a second time period; firing pin means operatively affixed to said housing and releaseably held in said triggering means; a fuze cover circumambient said housing having an integrally formed disturbance weight position lock and a disturbance switch pivot depending from the inside top surface of said cover; a disturbance means, held by said switch pivot operatively adjacent to said cover, and rotationally responsive to said munition movement after said first time period; and a delay means operatively positioned intermediate said disturbance means and said triggering means for keeping said disturbance means inoperative during said first time period, initiating said munitions upon movement of said fuze after expiration of said first time period, and for the initiation of said munition after said second time period.
 2. An anti-disturbance delay fuze as recited in claim 1 wherein the triggering means comprises: a cylindrically shaped rotor having a bottom end with an axially positioned annular groove therein, an axial rotor shaft concentric with said annular groove further including a radially positioned shaft recess for releasably holding said firing pin means therein, a top end having a plurality of bar-shaped vanes radially mounted thereon and extending in a direction normal to said central bore, wherein one of said bar vanes is longer in length; and a biased helical spring wound around said rotor intermediate said vanes and said bottom end having a first end anchored to said housing and a second end fixed to said rotor.
 3. An anti-disturbance delay fuze as recited in claim 2 wherein the firing pin means comprises: a cylindrical shaft having a flat end and a pointed end, a radial recess transverse to its longitudinal axis and intermediate to said flat and pointed end; and a ball lock operatively positioned intermediate said firing pin shaft recess and said rotor shaft for holding said firing pin in a ''''safe'''' position during said first time period, and for releasing said firing pin when said rotor radially positioned recess aligns itself with said ball lock.
 4. An anti-disturbance delay fuze as recited in claim 3 wherein the disturbance means comprises: a pivotal member rotatably held by said switch pivot; a switch contact column depEnding from one end of said member; a bent flexible cantilevered moment arm fixedly attached to the other end of said member; and a pendulous mass, fixedly attached to said moment arm, so that a counterbore in said mass operatively engages said position lock when said fuze is in a safe position and is free to rotate about said switch pivot when said fuze is in an ''''armed'''' position.
 5. An anti-disturbance delay fuze as recited in claim 4 wherein the delay means comprises; a disc pivotally held in said disc counterbore, having a disc switch column fixedly attached to its upper side and axially aligned with said member switch column, a U-shaped release lever, including upper and lower legs, said release lever pivotally attached to said disc and operatively positioned so that said upper leg supports said pendulous mass when said triggering means during said first period supports said lower leg; and a pliable sac having a viscous fluid therein sealed to said disc underneath side intermediate to said disc and said plurality of vanes.
 6. An anti-disturbance delay fuze as recited in claim 5 wherein the viscous fluid is a silicone gum. 